Advanced composite materials offer several advantages which make them very viable for use in constructing tension leg platform tendons for use in deepwater application. These advantages include light weight, high strength, high elastic modulus and corrosion resistance. Two approaches have been advanced for composites, one is used to use composite cables and the second is to use composite tubulars. Composite tubulars offer several advantages over ropes or cables. For example, they can be designed with positive buoyancy, they allow easy inspection and the internal space in the tubular can be used to activate the lower anchor connector of the tendon using a hydraulic fluid. For TLP applications, the design of tendons is primarily controlled by the axial stiffness. High axial stiffness which is required necessitates that the fibers in the composite tubular be laid in a near axial direction which makes both the fabrication using conventional filament winding process and termination using adhesively bonded joint almost impractical. Also, if another extrusion process such as pultrusion is considered, rather than the filament winding process, it may not be suitable because the tubulars require some helical layers of fibers to provide the necessary pressure resistance. This makes filament winding the most practical construction route for such tubulars. Since TLP tendons are subjected to high axial loads, the use of a conventional termination that relies on the shear strength of the interface between the composite and the termination is not suitable.
It would be desirable to provide a termination which can be used with composite tubulars and which has sufficient shear strength to satisfy the requirements of tension leg tendons for tension leg platforms.